1. Field of the Invention
This invention relates to jet nozzles. More specifically, the invention is a jet nozzle arrangement that incorporates a coaxial centerbody having a shape that enhances the mixing of exhaust exiting the nozzle exit area.
2. Description of the Related Art
In the field of jet nozzle design, researchers are always looking for ways to reduce jet noise while optimizing thrust performance. One current jet nozzle design has a nozzle with a conically-tipped centerbody coaxially aligned within the nozzle. For example, FIG. 1 depicts a cutaway perspective view of a two-contour, separate flow, co-annular nozzle arrangement that is referenced generally by numeral 100. Nozzle arrangement 100 includes an external nozzle portion 102, an internal nozzle portion 104 and a centerbody 106 having a conical tip 108 coaxial within internal nozzle portion 104. Nozzle arrangement 100 can be used in subsonic or supersonic applications.
In the subsonic regime, conical tip 108 of centerbody 106 resides within internal nozzle portion 104 as shown. For the production of additional thrust required for the supersonic regime, centerbody 106 is moved (by an actuator that is not shown) axially so that conical tip 108 extends beyond the exit areas of external and internal nozzle portions 102 and 104, respectively. External nozzle portion 102 and internal nozzle portion 104 could also be moved axially to change the nozzle exit area and corresponding average jet exhaust Mach number. Reduction of noise is one of the ongoing studies associated with this and other centerbody-type nozzle arrangements.